Archive for the ‘Green Patents’ category

Flexibility = Reliability: Nordic Windpower’s Teetering Turbine

July 29th, 2009


Nordic Windpower (Nordic) is a Berkeley, California company that designs, manufactures and sells utility-scale wind turbines. 

Earlier this month Nordic announced that it had received a $16 million loan guarantee offer from the U.S. Department of Energy.  Nordic said it will use the government funds to expand its Idaho assembly plant.

Nordic’s turbines have a two-blade design rather than the more traditional three-blade rotor common in utility-scale wind.

A two-blade design reduces the cost associated with providing blades and simplifies assembly but also requires a different hub design because a two-blade turbine is less balanced and more prone to fatigue from that unbalance than the conventional three-blade turbine.

Teeter hubs, which are hinged to the turbine shaft, were developed for two-blade turbines, but they don’t hold up well in extreme wind conditions.

Nordic has developed flexible teeter hub technology so the rotor blades can flex at the hub to dissipate high winds before they can reach or damage the turbine drive train.  International Pub. No. WO 02/079647 (’647 Application) describes and claims Nordic’s flexible teeter hub assembly. 

The ’647 Application is directed to a teeter hub (2) that allows some flexing while also better absorbing extreme torque.  Blades (1) are connected to the hub (2), and the hub is connected to the turbine shaft (3). 

The reaction arm (15) extends all they way through the hub (2) from the periphery adjacent the turbine shaft (3) to the opposite side of the hub.  The length of the reaction arm (15) allows the hub assembly to better absorb extreme torque caused by high winds.


The bearing (12), the reaction arm (15) and the spring elements (13) together form a hinge assembly.  When high winds blow, the hinge assembly allows the hub (2) to pivot slightly while the springs (13) counteract the teeter movement. 

The torque is absorbed with an even distribution on the bearing (12) and the springs (13) thus minimizing damage to the turbine.

Swift Overcomes Obviousness Rejections to Obtain Small Wind Turbine Patent

July 19th, 2009


In a previous post, I wrote about the new Swift wind turbine, developed by Scottish energy products and solutions company Renewable Devices Swift Turbines Ltd. (RDST) for use in densely populated areas.  Last month RDST obtained a patent for its turbine:  U.S. Patent No. 7,550,864 issued June 23, 2009.

RDST’s design overcomes the problem of wind turbine noise by using a circular diffuser (21) that rings the turbine blades.  In operation, when the airflow reaches the ends of the blades, it contacts the diffuser and proceeds in a circumferential path instead of flowing off the ends of blades.


The Swift turbine also has a furling device (50) with tailfins (53, 54).  When the airflow exceeds a certain speed, the furling device rotates the rotor to maintain the direction of the airflow in line with the turbine’s rotational axis.  In excessively high winds, the turbine rotor can be rotated out of the airflow altogether.  These measures reduce the vibrations of the turbine assembly components. 

Finally, the Swift turbine has a mounting structure that includes a rubber core to absorb vibrations before they spread upward to the moving parts of the turbine assembly.

RDST overcame rejections by the U.S. Patent & Trademark Office that its patent claims were obvious over two prior art patents by using a host of arguments, including some of the so-called “secondary considerations” of non-obviousness.

Independent claim 1, as amended during prosecution (and as ultimately issued) recited:

A rotor for a roof-mounted wind turbine comprising a plurality of radial blades and a ring-shaped diffuser connected to the outer tips of the blades, wherein the diffuser is an aerofoil diffuser and is configured such that it inhibits the partly axial and partly radial airflow from the blades, said airflow becoming circumferential when it contacts the aerofoil diffuser, thereby reducing acoustic emissions.

Thus, the claimed turbine rotor contained the following mechanical components:  a rotor, a plurality of blades, and a ring-shaped diffuser, wherein the diffuser is an aerofoil diffuser.

The U.S. Patent & Trademark Office (PTO) viewed this iteration of claim 1 as a combination of known elements and rejected the claim as obvious over two prior art patents, one of which disclosed a rotor, blades and a diffuser and another that taught an aerfoil diffuser.  According to the patent examiner, it would have been obvious to combine the aerofoil diffuser of reference two with the rotor blades and diffuser of reference one to achieve a reduced noise level.

RDST successfully overcame this rejection by pointing out deficiencies in the cited prior art and by using a host of non-obviousness arguments.  For instance, RDST argued that the prior art taught away form attaching a large mass to the ends of rotor blades, that the degree of noise reduction was an unexpected result and that competing designs had failed to achieve comparable noise reduction.

Finally, to tie it all together for the patent examiner, RDST submitted audiovisual evidence of the its quiet turbine in action.

Potter Drilling’s Geothermal Spallation Innovation

July 15th, 2009


Potter Drilling, LLC (Potter) is a Redwood City, California-based company that develops drilling technology for various applications, including geothermal energy production.

Potter specializes in novel drilling systems that don’t require contact between the drill assembly and the rock in order to make holes in the geological formation.  Specifically, the company’s key innovations involve a process called spallation, which uses high intensity fluid streams to fracture rock surfaces. 

A common problem that arises during deep drilling is that non-uniform stresses are created around the borehole, which cause the rock around the hole to break out; this can make a circular hole become non-circular.  Pieces of rock can fall into the hole, causing the drill or casing to get stuck.  This phenomenon is aptly named ”breakout.”

Potter’s drilling processes take a proactive approach to this problem by intentionally creating non-circular boreholes to avoid inadvertent and uncontrolled breakout.

In addition, Potter developed a technology to produce non-circular boreholes for ground source heat pump (GSHP) applications where it is desirable to separate the tube carrying water down the hole from the tube carrying water back up in order to reduce heat exchange between the different temperature streams. 

Potter owns U.S. Patent Application Pub. No. 2008/0093125 (’125 application), entitled “Method and system for forming a non-circular borehole”, which describes some of the company’s drilling technologies for creating shaped boreholes.  

One of those is particle drilling for GSHP applications, which uses particles in an air stream to cut the rock.  This technology is being developed by a spinoff company called Ground Source Geothermal.

I talked to Dr. Tom Wideman, Potter’s CTO, who told me (no pun intended I think) that the company’s “most groundbreaking” technology is hydrothermal spallation.

Hydrothermal spallation uses hot water to cut through rock.  According to the company’s web site, hydrothermal spallation was invented and patented by Potter’s co-founder Robert Potter and Jefferson Tester of MIT. 

Potter is the exclusive licensee of U.S. Patent No. 5,771,984 (’984 patent), which is owned by MIT and directed to apparatus and methods of excavation by hydrothermal drilling. 

The ’984 patent covers a jet housing (602) rotatably mounted to a flow pipe assembly support (604).  The jet housing (602) contains two or more combustion chambers (610).  


Jet housing (602) contains passageways (614) for cooling water, passageways (616) for the fuel and passageways (618) for the combustion air.  It also has a central conduit (620) for the escaping combustion gases and returning flakes of rock. 

The hot fluid products of thermal combustion are jetted downward onto the rock though nozzles (612) located near the outer circumference of the bottom of the drilling apparatus.

This Clean Technica piece calls Potter’s hydrothermal spallation drill the “Holy Grail” of geothermal because of the promise that it can drill faster, deeper and cheaper than prior drilling systems. 

Potter is continuing its spallation innovation and patenting.  Wideman described Potter as an “IP-rich company” and told me the company has multiple recently-filed patent applications in the pipeline.

Eamex’s Polymer Capacitor to Compete with Lithium Ion Batteries?

July 9th, 2009


Eamex Corp. (Eamex) is a Japanese company that has developed a high energy density capacitor using a proprietary polymeric actuator with metal plating that serves as an electrode.

The capacitor and methods of making it are covered by U.S. Patent No. 7,169,822 (’822 patent).  The ’822 patent is directed to a polymeric actuator (1) comprising an ion-exchange resin (2) in the form of a flat plate or film and metal electrodes (3a, 3b) attached to the surface of the resin by chemical plating techniques.


Lead wires (4a, 4b) provide an electrical connection between the electrodes (3a, 3b) and a power source (5).  The metal electrodes (3a, 3b) are insulated from each other, and application of a potential difference between the electrodes causes the ion-exchange resin product to bend or deform.

According to Eamex’s web site and this Greentech Media article, the electrodes of the patented actuator have greatly increased surface area, and the energy density per unit volume reaches up to 600 Wh/L, which is equivalent to that of a lithium-ion secondary battery.

SPAWAR’s Licensable Green Patents

July 5th, 2009


The U.S. Navy lab here in San Diego, also known as SPAWAR (an acronym for Space and Naval Warfare) has over 300 licensable technologies.  According to Claire Dobransky in SPAWAR’s technology transfer office, these include around 10 opportunities in the clean tech space. 

Ms. Dobransky told me that the clean technologies are high priority items for the lab, which is looking to spin off the innovations to the commercial sector.

One interesting SPAWAR patent is U.S. Patent No. 6,433,465, entitled “Energy-harvesting device using electrostrictive polymers” (’465 patent).  The ’465 patent is directed to an apparatus for harvesting electrical power from a person’s walking movements using the electrical response phenomenon of electrostrictive polymers.

The approach taken by the ’465 patent is to incorporate an energy-generating polymer (16) into the sole (14) of a shoe (12).  The polymer (16) is hooked into circuitry (24), which is in turn connected to an electrical cord so the generated electricity can be used or stored by the person wearing the shoe.


Other patents identified as clean technology offerings by SPAWAR include:

U.S. Patent No. 6,147,754, entitled “Laser induced breakdown spectroscopy soil contamination probe”;

U.S. Patent No. 6,406,777, entitled “Metal and glass structure for use in surface enhanced raman spectroscropy and method of fabricating the same”;

U.S. Patents Nos. 7,424,375 and 6,993,437, entitled “Tidal seepage meter”;

U.S. Patents Nos. 7,437,959 and 7,444,891, entitled “In-water hull cleaning sampling device”, and “In-water hull cleaning sampling method”, respectively;

U.S. Patent No. 7,153,749, entitled “Method of tuning threshold voltages of interdiffusible structures”; and

U.S. Patent No. 5,925,370, entitled “Bio-repellent matrix coating”.

For many of its offerings, SPAWAR provides a handy informational “tip sheet,” such as this one for the hull cleaning technology (spawar_in-water-hull-cleaning-tip.ppt). 

A complete list of the SPAWAR technologies available for license can be found at its Available Technologies page.

Clean Energy Patent Index Shows Slight Drop in Q1 2009

July 2nd, 2009

The clean energy patent tallies for the first quarter of 2009 came out last month.  The first quarter report of the Clean Energy Patent Growth Index (CEPGI), run by the Heslin Rothenberg law firm, found that the number of U.S. patents granted in the clean energy sector fell slightly in the first quarter of this year.

According to CEPGI, 243 clean energy patents were granted in the first quarter of 2009, which was a slight drop from the 261 granted in the fourth quarter of 2008.  However, it was a relative gain from the first quarter of last year, in which the U.S. Patent & Trademark Office (PTO) granted 220 clean energy patents.

This drop comes in the wake of a record year:  in 2008, 928 clean energy patents issued in the U.S.

As to the technologies being patented, fuel cells are the most represented but fell from 140 to 133 from the previous quarter.  Wind, solar and tidal / wave energy patents also dropped in the first quarter of 2009, but patents relating to biofuels and hybrid and electric vehicles rose.

The top 10 clean energy patentees in Q1 2009 included automakers such as Honda, General Motors, Toyota and Nissan with a host of fuel cell patents and some hybrid vehicle patents.  Other companies in the top ten included Panasonic, General Electric, Samsung and Enercon.

Last year’s first quarter report also found a drop in granted clean energy patents relative to the fourth quarter of 2007.  One possible explanation for first quarter dips is that the PTO issues more patents in the fourth quarter of the year than in the first quarter, perhaps because patent examiners try to wrap up cases at the end of the year.

Kruse Sues Again; Accuses Isuzu of Infringing Diesel Engine Patents

June 25th, 2009


In a previous post, I wrote about Kruse Technology Partnership’s (“Kruse”) infringement suit against DMAX, Ltd. (“DMAX”), an Ohio diesel engine manaufacturer formed as a joint venture between GM and Isuzu.  

In that case, Kruse alleges that DMAX’s Duramax engines infringe three related Kruse patents:  U.S. Patent Nos. 5,265,562 (“’562 patent”), 6,058,904 (“’904 patent”) and 6,405,704 (“’704 patent”).

Last month Kruse filed a second lawsuit, this time targeting Isuzu.  The complaint (kruse-isuzu-complaint.pdf), filed in federal court in Santa Ana, California, asserts the same patents and alleges that Isuzu’s diesel engines infringe the patents.

The asserted patents are directed to Kruse’s “Limited Temperature Cycle” technology, which reduces combustion temperature, boosts thermal efficiency and reduces certain chemical emissions by diesel engines by injecting fuel in multiple increments.   

The patents describe an engine (10) comprising a block (12), a cylinder head (14) and a cylinder (16) having a piston (18).  Fuel is supplied to the engine (10) by a fuel injection system (36).  The engine (10) also includes an air induction system (26) having an air intake valve (28) in the cylinder head (14).


The process maintains a proper fuel/air mix in the engine to reduce the temperature and the work of compression.  According to the ’904 patent, the fuel injection system (36) precisely regulates this fuel/air mixture for combustion and exhaust emission control.

The complaint requests that the court issue a permanent injunction against Isuzu and award Kruse compensatory damages for the alleged infringement.

Wanna Buy A Wind Power Patent? Just Go to eBay

June 21st, 2009


Fellow green patent enthusiast Stu Soffer brought this interesting item to my attention (Thanks Stu!):  an eBay auction for the rights to a small wind turbine patent.  The patent is New Zealand Patent No. 540102, and includes the international rights to PCT Application Pub. No. WO 2006/123951 (’951 application).

The ’951 application is directed to a wind turbine having a rotor (1) having blades, the rotor rotatably mounted about the axis of rotor shaft (2) within housing (3).  Directional louvers, or shutters (15, 17), direct incident airflow to enhance the venturi effect and reduce drag for maximum power generation.


Though at first glance it appears the seller is only auctioning the rights to the patent application, the description of the transaction reveals that a purchaser would get substantially more than that (or less, depending on your point of view).  In fact, the purchaser would also buy an obligation to enter into a partnership with the inventor:

What is being sold is the US rights to patent protection vested in a company substantially owned by the purchaser. The purchaser will have written authority from the inventor to assign the US intellectual property rights to the new company. All the inventor requires apart from the purchase price is a small shareholding of 10% of the shares in the new US company as a silent partner that the buyer will create by agreement, and acknowledgement that the invention was created by the inventor at all times. 

The seller is offering free shipping, although what this means in this context is not entirely clear.  Would the buyer receive in the mail the patent application?  A prototype of the invention?  An executed assignment?

The opening bid price is USD $27,500.  The auction ends on June 24, 2009, and there have been no bids so far.

New Prius Has Silicon Sun Roof By Kyocera

June 18th, 2009


Kyocera recently announced that it is supplying solar modules for Toyota’s new solar ventilation system, an optional feature on the new Prius introduced in Japan last month.

The modules will be made using the company’s Reactive Ion Etching (RIE) technology, which creates microscopic ridges on the surface of the solar cell using plasma and reductive gases.  According to Kyocera’s press release, the ridges enhance output and conversion efficiency by facilitating better absorption of sunlight. 

The process also yields a “high level of aesthetic quality” and “stylish appearance” by providing a uniform dark navy blue color.

This RIE process is covered by Kyocera’s U.S. Patent No. 7,128,975 (’975 patent), entitled “Multicrystalline silicon substrate and process for roughening surface thereof.”  The ’975 patent is directed to a multicrystalline silicon substrate and a process for roughening the substrate’s surface using an alkaline aqueous solution etching step and a dry etching step.

According to the ’975 patent, this process overcomes the challenge of forming uniform textures in the irregular crystal orientation of multicrystalline substrates and reduces reflectance:

By this method, fine textures can be uniformly formed independent of the irregular orientation of the crystals of multicrystalline silicon. In particular, reflectance can be more effectively reduced in solar cells using multicrystalline silicon.

The ’975 patent describes a silicon substrate (1) formed by the patented RIE process as having textures (2), or fine textures (22).  According to the ’975 patent, the ratio of line a (connecting individual peaks of the fine textures (22)) and line b (connecting the two end points 23 and 24) is less than 1.1, which indicates that the heights of the peaks of the fine textures (22) are even.


Congress Backs Strong Green Patents in Climate Change Talks

June 14th, 2009

The U.S. House of Representatives voted unanimously last week to pass an amendment to the Foreign Relations Authorization Act that establishes U.S. policy in opposition to any global climate change treaty that would weaken intellectual property rights.  (see the National Journal article here)

The bill increases resources and training for enforcement of intellectual property rights.  Under the bill, the U.S. Secretary of State would appoint ten new IP attaches to serve in U.S. embassies or other diplomatic missions.  The bill gives priority placement to countries with particularly poor IP regimes. 

The amendment, offered by Reps. Rick Larsen (D-Wash.) and Mark Kirk (R-Ill.), and passed 432-0, provides an unequivocal statement that U.S. policy favors strong IP rights for clean technologies as part of any climate change treaty:

it shall be the policy of the United States that, with respect to the United Nations Framework Convention on Climate Change, the President, the Secretary of State and the Permanent Representative of the United States to the United Nations should prevent any weakening of, and ensure robust compliance with and enforcement of, existing international legal requirements as of the date of the enactment of this Act for the protection of intellectual property rights related to energy or environmental technology. . .

The amendment is a timely policy message as diplomats are preparing for key negotiations as part of the U.N. Framework Convention on Climate Change (UNFCCC) in Copenhagen in December.

The amendment comes on the heels of the launch of the IDEA Coalition, an alliance of business and industry leaders formed to educate policymakers and the public about the importance of strong IP protections in promoting clean tech innovation. 

One of the Coalition’s first orders of business was to urge Congress and the Obama administration to maintain strong IP protection for clean tech innovators as the U.S. engages in international talks related to the UNFCCC.  Looks like a quick success for the Coalition right out of the box. 

According to Carl Horton, Chief IP Counsel for GE, the amendment was in large part a result of the IDEA Coalition’s activities.  He told me the Coalition briefed Congressmen Larsen and Kirk “regarding the risk to IP protection for green technology at the UNFCCC negotiations.”

Advocates of strong IP protection are pleased with the Larsen amendment and the message it sends about the U.S. position on IP rights in clean technologies.  Horton thinks the amendment “sends a powerful message about the necessity for strong IP protection to drive investment and innovation in new green technologies and the need to endorse such IP protection as the means to protect the US jobs created by such green technologies.”